Vacuuming Device Comprising a Vacuum Cleaner and a Bag Filter

ABSTRACT

The invention relates to a vacuum-cleaning apparatus comprising a vacuum cleaner and a filter bag, in which the filter bag is formed as a non-woven fabric filter bag, as a disposable filter bag and as a flat bag having a first filter bag wall and a second filter bag wall, the filter bag has at least one surface fold, wherein each surface fold comprises areas that are positioned within the surface area of the filter bag wall, and areas that project over the surface area of the filter bag wall and can be unfolded during the vacuum-cleaning, the vacuum cleaner comprises a filter bag receiving space with rigid walls, wherein on the walls of the filter bag receiving space at least a first spacer device is provided to space the areas of at least one surface fold positioned within the surface area of the filter bag wall away from the wall of the filter bag receiving space, and at least a second spacer device is provided to space the unfolded areas of the at least one surface fold away from the wall of the filter bag receiving space.

FIELD OF THE INVENTION

The invention relates to vacuum cleaning apparatus comprising a vacuumcleaner and a filter bag which is formed as a non-woven fabric filterbag, as a disposable filter bag and as a flat bag with surface folds.

PRIOR ART

Filter bags in the form of disposable flat bags and made of a non-wovenfabric are those filter bags that are nowadays most commonly used. Theadvantage of non-woven fabric bags (as opposed to filter bags made ofpaper) is the substantially higher dust absorption capacity of thefilter bag, along with a high collection efficiency and longer servicelife. The flat bag shape is the most widely spread shape for non-wovenfabric bags as bags having this shape are very easy to manufacture. Asopposed to the paper filter material used for paper filter bags thenon-woven fabric material is very hard to fold permanently owing to thegreat resilience, so that the manufacture of more complex bag shapes,such as block bottom bags or other bag shapes having a bottom, is verycomplicated and expensive.

Rat bags as used in the present invention are filter bags whose filterbag wall comprised of two individual layers of a filter material withidentical surface areas is formed such that the two individual layersare connected to each other only at their circumferential edges (theterm identical surface area does not preclude, of course, that the twoindividual layers differ from each other by the fact that one of thelayers includes an inlet opening).

The connection of the individual layers may be realized by a weldingseam or adhesive seam along the total circumference of the twoindividual layers. However, it may also be realized such that oneindividual layer made of a filter material is folded about one of itsaxes of symmetry while the other, open circumferential edges of the socreated two sub-layers are welded or bonded to each other (so-calledtubular bag). Thus, this type of manufacture requires three welding orbonding seams. Two of those seams then form the filter bag edge. Thethird seam may equally form a filter bag edge or lie in one of thefilter bag walls.

An individual filter material layer taken by itself may, in this design,consist of one or more layers which can be laminated, for instance.

Rat bags as used in the present invention may also comprise so-calledgussets. These gussets may be fully unfoldable. A flat bag having suchgussets is shown, for instance, in DE 20 2005 000 917 U1 (see FIG. 1with folded gussets, and FIG. 3 with unfolded gussets). Alternatively,the gussets may be welded to sections of the circumferential edge. Sucha flat bag is shown in DE 10 2008 006 769 A1 (see FIG. 1 thereof).

It necessarily follows from the above definition of the term flat bagthat fiat bags are two-dimensional structures immediately after themanufacture thereof, i.e. they have an internal volume prior to theiruse that is substantially equal to zero.

However, a filter bag with an internal volume that is substantiallyequal to zero (prior to its use) is not necessarily a fiat bag withinthe meaning of the present invention, as bag shapes having a bottom, asdescribed for instance in DE 20 2005 016 309 U1 or DE 20 2009 004 433U1, are not flat bags because they are not formed of two individuallayers having identical surface areas that are connected to each otheronly at their circumferential edges.

In the light of the above definitions it is a matter of course that bagshapes that are already three-dimensional structures after theirmanufacture and, thus, have an internal volume different from zero, asare described for instance in WO 00/00269 (see FIGS. 27 and 28 thereof)and DE 10 2007 060 748 (see in particular FIG. 9 thereof), are not flatbags in accordance with the present invention.

A non-woven fabric bag in accordance with the present inventioncomprises a filter material of a non-woven fabric. Aft-laid or wet-laidnon-woven fabric, or an extruded nonwoven fabric, in particular amelt-spun micro-fiber spunbonded non-woven fabric (melt-blown non-wovenfabric) or filament spunbonded non-woven fabric (spunbond) may be usedas non-woven fabric material. In addition nanofiber layers may beprovided. The differentiation between wet-laid non-woven fabrics,respectively nonwovens, and conventional wet-laid paper is made inaccordance with the definition provided below, which is also used byEDANA (International Association Serving the Nonwovens and RelatedIndustries). Therefore, a conventional (filter) paper is not a non-wovenfabric.

The non-woven fabric may include staple fibers or endless fibers. Withregard to the manufacturing is is also possible to provide severallayers of staple fibers and endless fibers which are bonded to exactlyone layer of nonwoven fabric.

The filter material may also be a laminate made of several nonwovenfabric layers, e.g. filament spunbonded non-woven fabric and melt-blownnonwoven fabric (SMS, SMS or Sn×MS). Such a laminate may be laminated oralso calendered by means of a hot adhesive. The layer of melt-blownnonwoven fabric may be creped.

The term nonwoven fabric (nonwoven) is used according to the definitionin the ISO standard ISO 9092:1988, respectively standard EN 29092. Inparticular, in the field of the non-woven fabric manufacture the termsfibrous web or nonwoven and non-woven fabric are differentiated asdefined below, and should be understood in accordance with thisdefinition also within the limits of the present invention. To produce anonwoven fabric, fibers and/or filaments are used. The loose and stillnon-connected fibers and/or filaments are called nonwoven or fibrous web(web). In a so-called nonwoven bonding step a non-woven fabric isfinally created from such a fibrous web, the tenacity of which issufficient, for instance, to be wound to rollers. In other words, anon-woven fabric becomes self-supporting by the bonding. (Details aboutthe use of the definitions described herein and/or methods may be alsolearned from the standard work “Vliesstoffe”, W. Albrecht, H. Fuchs, W.Kittelmann, Wiley-VCH, 2000).

The filter bag wall comprises at least one surface fold. The design ofsuch surface folds is shown, for instance, in the European patentapplication 10163463.2 (see in particular FIG. 10a and FIG. 10b,respectively FIG. 11a and FIG. 11b thereof). If the filter bag wallcomprises a plurality of surface folds this material is also called apleated filter material. Such pleated filter bag was are shown in theEuropean patent application 10002964.4.

FIG. 1 and FIG. 2 show a cross-section of a filter bag comprising a wallwith two surface folds. Such surface folds enlarge the filter surface ofthe filter bag so that a higher dust absorption capacity of the filterbag, along with a high collection efficiency and longer service life isobtained (as compared with a filter bag having same outer dimensions andwithout surface folds).

FIG. 1 shows a filter bag 1 comprising a filter bag wall 10 with twosurface folds 11 in the form of so-called dovetail folds. The figureshows a cross-section of the filter bag through the filter bag center.The longitudinal axes of the surface folds accordingly extend in oneplane which, again, extends perpendicular to the plane of projection,and the surface folds extend at theft longitudinal ends into the weldingseams of the filter bag which extend in parallel to the plane ofprojection and are positioned in front of and behind the plane ofprojection. Thus, the strongest unfolding of the surface folds is in themiddle thereof. The filter bag is here shown in a state in which thesurface folds are already unfolded to some extent. Each dovetail fold 11includes areas 11 a positioned within the surface area of the filter bagwall 12, and areas 11 b projecting over the surface area of the filterbag wall 12. These areas lib are not yet unfolded when inserting thefilter bag into the vacuum cleaner for the first time.

FIG. 2 shows a filter bag 2 comprising a filter bag wall 20 with twosurface folds 21 in the form of so-called triangular folds. The figureequally shows a cross-section of the filter bag through the filter bagcenter. The longitudinal axes of the surface folds accordingly extend inone plane which, again, extends perpendicular to the plane ofprojection, and the surface folds extend at their longitudinal ends intothe welding seams of the filter bag which extend in parallel to theplane of projection and are positioned in front of and behind the planeof projection. Thus, the strongest unfolding of the surface folds is inthe middle thereof. In this case, too, the filter bag is shown in astate in which the surface folds are already unfolded to some extent.Each triangular fold 21 includes areas 21 a positioned within thesurface area of the filter bag wall 22, and areas 21 b projecting overthe surface area of the filter bag wall 22. These areas 21 b are not yetunfolded when inserting the filter bag into the vacuum cleaner for thefirst time.

The second filter bag wall of the filter bag illustrated in FIG. 1 andFIG. 2 does not have surface folds. Of course, this second filter bagwall, too, may comprise one or more surface folds.

Apart from the surface folds illustrated in FIG. 1 and FIG. 2 surfacefolds having different shapes are feasible, too. It should not beregarded as a limitation that the surface folds in the embodiments ofFIG. 1 and FIG. 2 extend perpendicular to a bag edge. Of course, thesurface folds may also extend at an angle to the bag edges.

Vacuum cleaners according to the prior art have filter bag receivingspaces with rigid walls. For a filter bag to develop its filter effectthese walls comprise spacer devices in the form of ribs, respectivelyrib-shaped sections to prevent the filter bag from bearing with itsfilter surface against the wall of the filter bag receiving space, thusreducing the effective filter effect.

DESCRIPTION OF THE INVENTION

In the light of this prior art it is the object of the invention toimprove the vacuum cleaning apparatus comprising a vacuum cleaner and afilter bag as known from the prior art in such a way that the dustabsorption capacity of the filter bag is further increased, along with ahigher collection efficiency and longer service life.

This object is achieved by a vacuum-cleaning apparatus comprising avacuum cleaner and a filter bag according to patent claim 1, viz. by anapparatus in which the filter bag is formed as a non-woven fabric filterbag, as a disposable filter bag and as a flat bag having a first filterbag wall and a second filter bag wall in which the filter bag has atleast one surface fold, wherein each surface fold comprises areas thatare positioned within the surface area of the filter bag wall, and areasthat project over the surface area of the filter bag wall and can beunfolded during the vacuum-cleaning, in which the vacuum cleanercomprises a filter bag receiving space with rigid walls, wherein on thewalls of the filter bag receiving space at least a first spacer deviceis provided to space the areas of at least one surface fold positionedwithin the surface area of the filter bag wall away from the wall of thefilter bag receiving space, and at least a second spacer device isprovided to space the unfolded areas of the at least one surface foldaway from the wall of the filter bag receiving space.

By providing this (these) special spacer device(s) for the areas of thesurface fold(s) positioned within the surface area of the filter bagwall and the special spacer devices for the areas of the surface foldprojecting over this surface area the surface fold can unfold in such away that the major part of the surface area of the filter materialforming the surface fold becomes exposed to a flow. Thus, the effectivefilter surface of the filter bag is enlarged (as opposed to the use in aconventional vacuum cleaner) so that the dust absorption capacity of thefilter bag, along with a higher collection efficiency and higher servicelife, can be further increased as compared to this conventionalapparatus.

According to a preferred further development of the invention the heightof the first and/or the second spacer devices with respect to the wallof the filter bag receiving space may be in a range of 5 mm to 60 mm,preferably of 10 mm to 30 mm. These dimensions allow an optimaladaptation of the filter bag receiving space to filter bags with surfacefolds.

Corresponding to another further development of the above-describedinventions each first and each second spacer device may be formed as aweb, a web-shaped section, a bow, a bow-shaped section, a rib, arib-shaped section and/or a lug. This further development allows acomparatively uniform, optimal flow exposure of the filter surface ofthe total filter bag inside the filter bag receiving space of the vacuumcleaner.

According to another further development of the above describedinvention each first and each second spacer device may be formedintegrally with the wall of the filter bag receiving space. Thus, thefilter bag receiving space of the vacuum cleaner may be manufactured byan injection molding process. This ensures a simple and inexpensivemanufacture of the filter bag receiving space.

Alternatively, all first and all second spacer devices may also beformed as a cage-shaped insert which is provided in the filter bagreceiving space. By this further development it is possible to retrofitalready existing vacuum cleaners. In this design, the cage-shaped insertmay be formed to be removable from the filter bag receiving space andinsertable into the filter bag receiving space.

According to a further development of all above-described inventions thefilter bag may comprise several, preferably three to seven surface foldsin the first layer of the filter bag wall and/or several, preferablythree to seven surface folds in the second layer of the filter bag wall.Surprisingly, it has shown that this configuration allows the optimumratio between the dust absorption capacity of the filter bag, along witha high collection efficiency and long service life, and a cost-efficientproduction of the filter bags.

BRIEF DESCRIPTION OF THE DRAWING

The attached drawing serves to explain the prior art and the invention,in which

FIG. 1 shows a filter bag according to the prior art with two surfacefolds in the form of dovetail folds;

FIG. 2 shows a filter bag according to the prior art with two surfacefolds in the form of triangular folds;

FIG. 3 a first embodiment of the present invention; and

FIG. 4 a first embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 3 shows a first embodiment of the present invention. Thisembodiment is particularly suited for a filter bag with dovetail foldsas illustrated in FIG. 1.

FIG. 3 shows the filter bag with fully unfolded surface folds 31. Theareas 31 a, which are positioned within the surface area of the filterbag wall 32, are spaced away by a first spacer device 35 from the wallof the filter bag receiving space 33. The areas 31 b, which project overthe surface area of the filter bag wall 32, are spaced away by a secondspacer device 36 from the wall of the filter bag receiving space 33.

As is recognizable in FIG. 3, the height of the first and second spacerdevices depends on both the size of the surface fold and the shape ofthe filter bag receiving space. If the filter bag receiving space has,in accordance with the embodiment of FIG. 3, a shape that is similar tothe shape of the filter bag in operation the spacer devices may beformed smaller than in a case where the filter bag space issubstantially cuboid-shaped, as is common in the prior art. In thelatter case, in particular if the filter bag comprises several surfacefolds, the first spacer devices for the various surface folds will alsohave a different size. The same applies to the second spacer devices(see in this respect the embodiment discussed in connection with FIG.4).

In the present case, the first and second spacer devices are formed asweb-shaped sections which extend section-wise along the surface fold.

According to this embodiment the first and the second spacer devices areformed integrally with the wall of the filter bag receiving space 33.This allows a simple production of the filter bag receiving space, forinstance by an injection molding process.

Alternatively, the first and second spacer devices may also be formed asribs, a rib-shaped section and/or a lug.

FIG. 4 shows a second embodiment of the present invention. Thisembodiment is particularly suited for a filter bag with triangular foldsas illustrated in FIG. 2.

FIG. 4 shows the filter bag with fully unfolded surface folds 41. Theareas 41 a, which are positioned within the surface area of the filterbag wall 42, are spaced away by a first spacer device 45 from the wallof the filter bag receiving space. The areas 41 b, which project overthe surface area of the filter bag wall 42, are spaced away by a secondspacer device 46 from the wall of the filter bag receiving space.

Regarding shape and size of the first and second spacer devices thestatements made in connection with the first embodiment applyanalogously.

According to a third, non-illustrated embodiment of the invention thefirst and second spacer devices are provided in the form of a cage. Theouter shape of this cage is predefined by the second spacer devicesspacing away the areas of the surface folds that extend beyond thesurface area of the filter bag wall. Usefully, all bars forming thesecond spacer devices run substantially parallel to each other andsubstantially parallel to the surface folds of the filter bags if theseare inserted into the cage as intended. Equally substantially parallelto these bars run the bars that form the first spacer devices. Thesebars reproduce the shape of the surface areas of the filter bag and,accordingly, extend into the interior of the cage formed by the secondspacer devices.

If necessary, it is also possible to provide cage bars which run at anangle, in particular perpendicular to the bars forming the first andsecond spacer devices. Such bars running at an angle serve to stabilizespecific areas of the filter bag, e.g. the area of the net opening.

1. Vacuum-cleaning apparatus comprising a vacuum cleaner and a filterbag in which the filter bag is formed as a non-woven fabric filter bag,as a disposable filter bag and as a flat bag having a first filter bagwall and a second filter bag wall, the filter bag has at least onesurface fold, wherein each surface fold comprises areas that arepositioned within the surface area of the filter bag wall, and areasthat project over the surface area of the filter bag wall and can beunfolded during the vacuum-cleaning, the vacuum cleaner comprises afilter bag receiving space with rigid walls, wherein on the walls of thefilter bag receiving space at least a first spacer device is provided tospace the areas of at least one surface fold positioned within thesurface area of the filter bag wall away from the wall of the filter bagreceiving space, and at least a second spacer device is provided tospace the unfolded areas of the at least one surface fold away from thewall of the filter bag receiving space.
 2. The apparatus according toclaim 1, wherein the height of the first or the second spacer deviceswith respect to the wall of the filter bag receiving space is in a rangeof 5 mm to 60 mm.
 3. The apparatus according to claim 1, wherein eachfirst and each second spacer device is formed as a web, a web-shapedsection, a bow, a bow-shaped section, a rib, a rib-shaped section or alug and combinations thereof.
 4. The apparatus according to claim 1,wherein each first and each second spacer device is formed integrallywith the wall of the filter bag receiving space.
 5. The apparatusaccording to claim 1, wherein all first and all second spacer devicescomprise a cage-shaped insert provided in the filter bag receivingspace.
 6. The apparatus according to claim 5, wherein the cage-shapedinsert is removable from the filter bag receiving space and reinsertableinto the filter bag receiving space.
 7. The apparatus according to claim1, wherein the filter bag comprises a plurality of surface folds in thefirst layer of the filter bag wall or a plurality of surface folds inthe second layer of the filter bag wall.
 8. The apparatus according toclaim 1, wherein the height of the first or the second spacer deviceswith respect to the wall of the filter bag receiving space is in a rangeof 10 mm to 30 mm.
 9. The apparatus according to claim 1, wherein theheight of the first and the second spacer devices with respect to thewall of the filter bag receiving space is in a range of 5 mm to 60 mm.10. The apparatus according to claim 1, wherein the height of the firstand the second spacer devices with respect to the wall of the filter bagreceiving space is in a range of 10 mm to 30 mm.
 11. The apparatusaccording to claim 1, wherein the filter bag comprises a plurality ofsurface folds in the first layer of the filter bag wall and a pluralityof surface folds in the second layer of the filter bag wall.
 12. Theapparatus according to dam 7, wherein the filter bag comprises three toseven surface folds in the first layer of the filter bag wall.
 13. Theapparatus according to dam 7, wherein the filter bag comprises three toseven surface folds in the second layer of the filter bag wall.
 14. Theapparatus according to claim 7, wherein the filter bag comprises threeto seven surface folds in the first layer of the filter bag wall andthree to seven surface folds in the second layer of the filter bag wall.